U.S. Pat. No. 6,457,514 of Oct. 1, 2002, IPC H05K7/20, describes a liquid cooled dissipator for electronic components characterized by selectively arranged dissipation fins, namely fins positioned only in proximity of the areas against which the electric components to cool are mounted.
The disadvantage of said device is in that local heat transfer rises in the areas where cooling modules have been installed because additional elements (fins, finned plates) are added to the flow of the cooling liquid resulting in increased hydraulic resistance of the coolant channels and the design costs.
Inventor's Certificate No. 1637051 of Mar. 23, 1991, IPC H05K 7/20, describes a radio electronic module unit that comprises a housing, circuit boards with several electronic components firmly affixed to one of their sides, and heat dissipater, consisting of laminated plates which form channels in which the cooling liquid circulates. In the module, circuit boards are connected to the heat dissipater with their unattached sides in order to increase composition density and improve heat transfer. The channels in which the cooling liquid circulates are located in the inner layer of the heat dissipater to ensure contact with the outer layers over their entire length and, in a longitudinal section, are structured in the form of a meander directed along the rows of electronic components.
The disadvantage of this invention is design that lacks effectiveness because heat is dissipated from the entire base surface and partially along the rows of electronic components.
The closest technical decision is a cooling device for power circuit modules, as described in Russian Patent No. 2273970 of Apr. 10, 2006, IPC H05K 7/20, which comprises a heat-dissipating base on which rows of heat-generating circuit modules and a lid are installed. The cooling device also includes channels in which the cooling agent circulates. The channels are structured in the form of a meander and the heat-dissipating base includes cavities made under the places where the electronic modules have been installed. The inserts installed in the cavities are connected with the lid and form the channels in which the cooling agent circulates. The channels are designed as straight-line portions and the meander sections that are interconnected and arranged in different planes. Each of these portions and sections is located in the cavity, wherein the channels are connected in a series-parallel pattern according to which the cooling liquid circulates. In order to mount electronic modules, the base has heat exchangers which go through the meander sections of the channels through which cooling liquid circulates. The heat exchanger portions located inside the channel are designed in the form of streamlined vanes, whereas in the places where the flow of the cooling liquid deflects and the cross sections of the channels in which the cooling liquid circulates is proportional to the power of the corresponding power electronic modules. The channels are equipped with rotary vanes. Thus, in order to reduce the hydraulic losses in each of the channels, the cross-sectional surface of the straight-line portions exceeds the cross-sectional surface of the meander sections. Furthermore, at least one of the channels in which the cooling liquid circulates, is equipped with a choke in order to balance the flow of the cooling liquid.
The cooling unit described above has the following disadvantages. The cooling agent heated after the first heat-generating electronic component is then passed to a second heat-generating electronic component. The process requires additional usage of the cooling liquid. This disadvantage is particularly evident when electronic components with different heat-generating parameters are used along the way the cooling liquid circulates. There are no structural elements that allow adjusting the supply volume of the cooling liquid for each electronic component individually and the speed of the cooling liquid in the channel, thus reducing the efficiency of heat transfer.
The technical result of the proposed technical solution is to increase the effectiveness and efficiency of a cooling system for a central processing unit (the CPU), simplify its design, improve reliability characteristics, and reduce energy consumption of the cooling system.
The technical result is achieved in that a cooling unit for the CPU comprises two flat grooved plates fastened together that jointly form at least one channel that is sealed by hermetic insert blocks and in which the cooling liquid circulates. These plates are heat-dissipating planes for heat-generating electronic components of the CPU that come into contact with them, while the channel in which the cooling liquid circulates has an inlet and an outlet, to supply and discharge the cooling liquid, respectively.
In this event, the electronic components of the CPU come into contact with flat plates directly through the pads and/or through various thermal interfaces. Accordingly, in a cut-away view, the channel in which the cooling liquid circulates may have the shape of a square, a rectangle, a circle, or an oval.
The flat grooved plates should preferably be mounted by fasteners or welded to each other. In this case, each flat plate has an insulated closed groove into which the hermetic insert blocks are mounted. In addition, two flat plates mounted together in their design may have fastening means for fastening the cooling unit to the wiring closet. The channel in which the cooling liquid circulates should preferably have a sequential pattern according to which the cooling liquid circulates.
In addition, an inlet and outlet must have the means to quickly connect hoses, pipes, or fittings, like John Guest fittings.
The operating principle of the cooling system for the CPU is to completely eliminate the heat gains generated in electronic components with the help of the cooling liquid. The cooling liquid moves along the channel preliminary formed in such a way as to reduce hydraulic losses and to level the temperature on the surface of the heat-generating components of the computer. A steady temperature of the computer components increases computer reliability as a whole. Energy savings are achieved by the following. The temperature of the insulated cooling liquid allows using atmospheric cooling and completely abandoning the Freon cooling systems and the like. The amount of cooling liquid that is required in order to remove the same heat gain is 4,000 times less than air volume equivalent in heat capacity. This is due to the heat capacity difference between different environments.
The cooling system suggested above comprises one or more cooling plates which are formed in such a way as to be connected to the heat-generating electronic components of the CPU directly or through different thermal interfaces. Among other electronic components, the cooling system is used to cool 2.5″ disks or one 3.5″ disk. The cooling plate is also used as a housing component and stiffens the structural integrity of the CPU.
The cooling liquid circulates inside the cooling plate in at least one channel. Thus, the cooling liquid removes heat gains from the surfaces of electronic components primarily due to contact heat transfer. The input and output of the cooling unit of the CPU are attached to the external liquid cooling system.